> > actually a single client doing nasty (non RT) stuff in its process()> > callback can "starve" jackd. AFAIK jackd waits until the last client> > has finished its process callback. So, if some client's process> > callback decides to use (for example) some blocking system call (big> > no no) and consequently falls asleep for a relatively long time, then> > it can cause jackd to miss its deadline. I'm not sure though wether> > this triggers an xrun in jackd or just a delay exceeded message.> > since the period size in Rui's test is so small (-p64 is 1.6 msecs?),

ca. 1.3ms

> the 2.6 msec timeout in pipe_poll() already generates an xrun.

yep. now the question is: why did jackd have to wait so long for theclient? what was the client doing? was it sleeping? what client was it?probably not the simple jack_test client, right?

Short tests ((20 minutes, due to lack of time) with cvs jackd and anumber of modified jack_test clients (added a for loop in the process()callback to burn cycles to increase the cpu load) show no xruns hereeven with relatively high cpu load (around 70%) and a periodsize of 64frames. Of course i had the mandatory additional kernel compile runningin the background :)

flo

Oh wow. Just before hitting send i got three xruns of around0.020-0.050msec. Ok, will read up on recent emails to see what to do todebug these.-To unsubscribe from this list: send the line "unsubscribe linux-kernel" inthe body of a message to majordomo@vger.kernel.orgMore majordomo info at http://vger.kernel.org/majordomo-info.htmlPlease read the FAQ at http://www.tux.org/lkml/